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The carbon cycle as a progenitor of the Anthropocene u The biosphere A complex adaptive system based on carbon Evolving for 3.5 billion years u The anthroposphere One species finds a new evolutionary trick: use of exosomatic energy Easiest energy source: detrital carbon from the biosphere Evolving for tens of thousands of years Biologically based, with extra technological, social, cultural levels

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Summary u The carbon cycle as a progenitor of the Anthropcene A key enabler of the Anthropocene is the use of exosomatic energy The primary energy source was, and remains, detrital biotic carbon u The contemporary carbon cycle Fossil-fuel CO 2 emissions have accelerated Partition fractions of anthropogenic CO 2 to air, land and ocean have been nearly constant, because emissions have grown nearly exponentially and the C cycle has been nearly linear The total CO 2 sink rate is decreasing, mainly through the ocean sink u Stabilising the carbon-climate-human system The task is to share a cumulative global quota on CO 2 emissions Full equity (population sharing) is not possible Attribution of historic emissions is not possible The most achievable sharing rule common to all major nations goes about 70% towards full equity